Just a heads up for those of us DIY types doing their first automatic transmission fluid change on a Ford product. When you drop the pan ( No drain Plug) you may be surprised to find you have a nice nylon shaped plunger complete with "O" ring laying in the bottom of the pan. The "Oh **** what now" immediately comes to mind. A quick look up into the dripping bottom of the transmission and nothing appears to accept this strange piece. I searched the forum achieves and found nothing. I was prepared to visit a Ford dealer and have them tell me that this is why you should always bring it to us lecture. Anyway , I kept searching the Web and found a post that addresses this strange extra piece. It turns out that Ford has a better idea and this piece is used in the transmission assembly process. It apparently just falls into the pan to roll around and be discarded at the first transmission service.

 

It's the dipstick tube plug. Haven't heard one of these stories in a while.